Michell, John, 1724?-1793

John Michell (; 25 December 1724 – 21 April 1793) was an English natural philosopher and clergyman who provided pioneering insights into a wide range of scientific fields including astronomy, geology, optics, and gravitation. He was the first to have proposed the existence of stellar bodies comparable to black holes, and was the first to apply statistics to astronomy, providing the earliest evidence for the physical nature of double stars and star clusters. He was first to have suggested that earthquakes travelled in (seismic) waves and the first to have measured the velocity of an earthquake, that being the 1755 Lisbon earthquake. Michell further invented an apparatus to measure the mass of the Earth that was later used by Henry Cavendish to measure the gravitational constant. He also explained how to manufacture an artificial magnet and provided the first accurate and comprehensive statement of the law of magnetic force. As a result, he has been called the father of both seismology and of magnetometry. Michell served as the Woodwardian Professor of Geology at the University of Cambridge starting in 1762. He was elected a Fellow of the Royal Society in 1760.